                A polymer electrolyte fuel cell includes cells, and each cell is configured by a membrane electrode assembly, a pair of gas channel forming members for holding the membrane electrode assembly in between, and a pair of separators for holding the gas channel forming members in between. The polymer electrolyte fuel cell is configured by stacking the cells together (see, for example, Patent Document 1).        
The membrane electrode assembly is configured by holding a polymer electrolyte membrane between a pair of electrode catalyst layers and is referred to as MEA. A gas diffusion layer is arranged on each of an anode-side surface and a cathode-side surface of the membrane electrode assembly.
In each of the gas channel forming members, a gas channel, through which fuel gas or oxidant gas flows, is formed between the surface facing the membrane electrode assembly and the membrane electrode assembly. In each gas channel forming member, a water channel for discharging generated water, which is generated through power generation, is formed between the surface facing the corresponding separator and the separator. A communication passage, which allows the gas channel and the water channel to communicate with each other, is formed in the gas channel forming member. The generated water, which is generated in the membrane electrode assembly through power generation, flows into the gas channel. Some of the generated water flows into the water channel through the communication passage and is discharged to the exterior via the water channel using flow pressure of the fuel gas or oxidant gas, which flows through the water channel.